Albert Barnes Commentary 1 Peter 1:21

"who through him are believers in God, that raised him from the dead, and gave him glory; so that your faith and hope might be in God." — 1 Peter 1:21 (ASV)

Who by him do believe in God. Faith is sometimes represented particularly as exercised in God, and sometimes in Christ. It is always a characteristic of true religion that a man has faith in God .

That raised him up from the dead. (Acts 3:15, 26; Acts 4:10; Acts 5:30; Acts 13:30; Romans 4:24; 1 Corinthians 15:15).

And gave him glory. By exalting him at his own right hand in heaven (Philippians 2:9; 1 Timothy 3:16; Ephesians 1:20–21).

That your faith and hope might be in God. That is, by raising up the Lord Jesus, and exalting him to heaven, he has laid the foundation of confidence in his promises, and of the hope of eternal life (See 1 Peter 1:3).

(Compare to 1 Corinthians 15; Colossians 1:27; 1 Thessalonians 1:3; 1 Timothy 1:1).